Complete gasification of solid fuel



Nov. 13, 1923.

C. W. ANDREWS COMPLETE GASIFICATION 0F SOLID FUEL Filed April 20.

Patented Nov. 13, 1923.

UNITED STATES CHARLES W. ANDREWS, OF DULUTH, MINNESOTA.

COMPLETE GASIFICATION OF SOLID FUEL.

Application med apra 2o. 1921.

To all `whom it ymay concern:

Be it known that. I, Cuantas W. AN- DREWS, a citizen of the United States, residing at Duluth, in the county of St, Louis, and State of Minnesota, have invented a new and useful Improvement in Complete Gasification of Solid Fuel, of which the following`is a specification.

The principal object of the present invention is to provide for the complete gasification of solid fuel in such a way that the operation is conducted with a degree of rapidity of throughput of' coal consonant with the best present day practice and in such a Way that the apparat-us employed is comparatively compact and inexpensive To these and other ends hereinafter set forth, the process, generally stated, consists in passing a fuel column through an externally heated vertical retort or chamber at a rate, established by the best present existing practice, and appropriate for the econo'mlcal production of coal gas and coal products at the upper part of the column and thus establishing a rate of coke travel or throughput for the lower part of the column, continuously converting substantially all of the coke throughput into water as by the introduction of steam at the ower part of the column, and co-ordinatng the rate of production of water gas with fie established rate of coke travel by providing a suliciently enlarged heat exchange surface in the lower portions of the column. The invention also comprises the yapparatus and improvements to be presently described and nally claimed.

In the drawings forming part hereof- Figure 1 is an elevational view principally in section, and

Fig. 2 is a horizontal section on line 2 2.

In the drawing 1 is a vertical retort or chamber externally heated through its walls and proportioned and adapted for the economical production Lf coal gas according to commercml practice. 2 is a Water gas generator communicating with the chamber 1 and externally heated through its wall and it is characterized by the fact that the area of its heat exchange` surface or wall 3 is sufficiently enlarged i insure that the temperature of substa ;1ally all the coke from the part 1 passing through it can be maintained sufliciently high for the Water gas production, thus providing for the manu- Serial NoA 462.992.

facture of water gas in co-ordination with the manufacture of coal gas and with the rate of feed of colte determined by the requirements of eflicient operation of the coal gas retort or chamber 1 and with the temperature at which the steam is introduced into it. The form of the water gas chamber 2 is not of the essence of the invention so 'i long as it has the necessary heat exchange surface. The combustion chamber 4 surrounds the water gas generator and extends froin approximately the bottom to the top thereof where it discharges to the recuperator direct or after passing around and heating the part 1, and it is shown as provided with baille plates 5. Into this chamber 4 there is appropriately introduced `air that may have been heated by a recuperdtor, not shown but well understood, and prefer; ably a portion of th blue gas, in most cases about half of it; however the mixed gas leaving the apparatus and after having been stripped and deprived of ammonia and tar may be4 used. 6 indicates an example of an air inlet, 7 an example of a gas passage, and 8 au example pf a connection to the recuperator. It is an important feature of my invention that the enlargement of the heat exchange surface of the part 2 need be materially less in cases where the steam introduced into the part 2 is highly superheated, for example, to substantially 1500o F. and preferably to a temperature above that required for the Iwater gas reaction. 9 is a superheating chamber for the steam and its wall 10 is also the wall of the combustion chamber 4, and' the relative location of the superheater and generator in the brickwork setting makes it practical to transfer such highly superheated steam, as by connection 11, without heat loss, but the steam may be highly heated by any suitable means.

In the practice of the invention by means of the described apparatus, solid fuel is fed downward through the externally heated vertical retort `or jciailnber 1 at a normal rate, that is to say, a rate appropriate for making coal' gas according to good commercial ractice. From the part 1 the hot coke reacllies the part 2, and is there fully utilized for the continuous manufacture of wl.- ter as, because the enlarged heat exchange sur ace and the temperature of the steam are such that th'iscan be done in co-ordinltion with the rate of travel of the colte which is fixed and established by the coal gas making` operation conducted in the part 1.

At the base of the retort the residue substantially free from carbon is delivered. Vith certaink'ndsof coal the ash may so adhere to the coke that even with my invention the ash coating will prevent the complete gasilication of all the coke in the water gas generator and in that case the coke can be reclaimed and utilized.

It will thus be seen that by this process coal is carbonized at a rate of throughput per unit of average cross section of the retort l which is not. less than that existing in the present best practice. To convert the resulting throughut of coke into blue gas requires the app ica-tion of so many heat unxts-for exempte, it requires about three times as much heat in 'art 2 as is required in part l-that hereto ore the' first step ot' the process was slowed down ,or the coke,

was removed and utilized elsewhere, but by my invention this' great number of heat units is -successfully supplied i n the part 2 without slowing down the first Step or removing coke from the apparatus., It-may be remarked that in some cases the blue gas leaving 2 at 7 may be, in whole or in part, carburcttcd and not burned in the cha'mber 4, and in that case' it is replaced by otherv fuel suitable for the chamber 4. f t

lt will be obvious to those skilled in the lishing r a rate of coke travel from the upper part of the column, converting substantially A all the coke into Water gas by the continuous introduction atv the lower part of the column of steam superheatcd tosubstantialliy the temperature of water gas reaction, and cofordinat'ng the rate of production of water'gas with the established rate of coketruvel by providing a sutiicicnlly enlarged 'heat exchange surface at the lower portion of the column.

3. The process of completely gasifying solid fuel which consists in establishing and externally heating a fuel column, permitting the column to descend at a rate substantially as described and appropriate for the economical production of coal gas at the upper part of the column thus establishing a rate of coke travel from the upper part of the column, converting substantially all the coke into water gas by the continuous introduction at the lower part of the column of steam superlieated above 1500o F., and co the column to descend at a` rate substantiallyas'described and appropriate for theiecojnomical production of coal gas at the upper art to whichthe invention relates that modiparlar/of the column thus establishing. a

fications may be made in details of proj cedure and construction without de artig from the spirit of the invention w ich is not limited as to those matters or otherwise than as the prior art and appended claims may require.

I claim: 1. The process of'completel vasifying solid fuel which consists in esta lis ing and externally heating 'a fuel column, permitting the column to descend at a rate substantially as describedA and appropriate for the economical production of coal gas at the uppgr part of the column thus establishing a rate of coke travel from the upper part of the column, converting substantially all the coke intowater gas by the continuous introduction of steam at the lower part of the column, and co-ordinating the rate of l duction of water as with the establised rate of coke trave, by` providing a rsulficiently enlarged* "t exchange surface 'at the lower portie the column.

2 The processi# completely gasifyingI solid fuel wh'fcli cisists instablishing an externally heating a fuelcolumn, permit# ting the column to descend itt4 a rate substantially as describedand appropriate for the economicalv production.A of coal gas' at the upper part of" the column thus estabrate of coke travel from the upper part of the column, converting substantially all the coke into water gas b the continuous introduction of steam at t e lower part of the column, co-ordinating the rate of roduction ofwater gas with the establis ed rate of coke travel by providinga suii-V ciently enlarged heat exchange surface at the lower portion of the column, and externally heatingl the column by the cornbusv tion of a portion of the gas enerated.

`5. The process of Vcomp etely gasifyiu solid fue] which yconsists in establishing an externullyheating a fuel column, permitting thecoluuoi to descend at a rate'substantially as ,described and ap ropriate for the economical production o coal gas at the upper part of the column thus establishing a rate- 6. Apparatus :for the complete sication nf Soid fuel comprising the com ination of un externally heated vertical coal gas retort or chg-@mnera an externaly heated water gas generator nponwhich the coal gas retort or cha rnberjs mounted sind with which it. communi- Gates, a combustion chamber, means foreon tinueusiy introducing steam inn seid water gas generator, a heat exchenge Wall area for the' water gas fenerator enlarged and eoordineted with t e coke delivery capacity of the coai gas retort or chamber 4to heat; substentiaily all of the coke substantially above the temperature of Water gas reaction, and a steam superheatin chamber the wall of which is commun to t e combustion chamber.

7. The combin ation of a brickwork setting, of a steam superheater provided therein, combustion chamber one well of which constitutes a, side of the steam superheater, a gas :linking chamber arranged in the combustlon chamber, and a connection through the brick werk from the steam superheater t0 the gas making chamber, whereby highly heated steam can be emloid,

l CHA L S W. ANDREWS. 

